1. Field of the Invention
This invention relates to an image forming apparatus and a method for assembling the apparatus. The image forming apparatus in this description is, e.g., a copying machine or a compound machine having various functions as copying machine, facsimile machine, printer, and scanner. The image forming apparatus has an image reader unit for reading an original image, and an image recorder unit for recording the image on a copy sheet based on image data read by the image reader unit or image data transmitted from an external device (such as facsimile machine).
2. Description of the Background Art
Generally, there have been known image forming apparatuses constructed in the following manner. First, a frame main body for the apparatus is constructed by assembling plural sheet metal products produced by a sheet metal working. Then, an image reader unit and an image recorder unit are mounted on the frame main body to obtain a main body of the apparatus. Further, a contact glass for setting an original document thereon is mounted at the top of the apparatus main body, and an original document presser for covering the entire plane of the contact glass is openably mounted on the apparatus main body.
Mounting the image recorder unit on the frame main body needs high precision. However, the conventional apparatus constructed in the above manner could not meet the demand for high-precision mounting because the image recorder unit was mounted on the frame main body constructed by assembling various sheet metal products. Accordingly, it took a long time to mount the image recorder unit on the frame main body of the conventional apparatus with high precision.
Further, since the frame main body is constructed by assembling various sheet metal products, the frame main body itself becomes rather expensive. This becomes one of the reasons for cost rise on the final product, image forming apparatus.
The conventional image forming apparatus also suffers from another drawback. All the components constituting the image forming apparatus need to be mounted on the single frame main body one by one according to the order. Accordingly, further the mounting step proceeds, more complicated the mounting operation that follows becomes. In addition, a series of mounting operations must be performed chronologically, resulting in lowering the mounting workability of the image forming apparatus.